This invention relates to communication between a computer and peripheral.
Computers often use peripheral devices such as hard disk drives and CD-ROM drives for data storage. A peripheral may include what amounts to a small computer of its own. This small embedded computer can control a variety of electronic and mechanical functions involved in data storage and retrieval such as controlling the positioning of a disk head that reads and writes data from a hard disk. The small peripheral computer can also handle software-oriented functions such as data caching and computer/peripheral communication.
Communication between a computer and peripheral is often governed by an industry standard such as the ATA standard (AT Attachment with Packet Interface Standard, Working Draft, Revision 18, published Aug. 19, 1998, available at ftp://fission.dt.wdc.com/pub/standards/x3t13/project/d01153r18.pdf). These standards can define the format, content, and sequence of messages exchanged between a computer and peripheral. These standards enable a computer to interact uniformly with a wide variety of peripherals made by different manufacturers.
In general, in one aspect, the invention features receiving a request at a peripheral for information describing at least one data-storage characteristic of the peripheral, and, without error, transmitting a reply including information falsely describing at least one data-storage characteristic.
In general, in another aspect, the invention features receiving a request at a peripheral from a computer for information, and transmitting a reply to the request that will cause a computer using a first computer/peripheral scheme not to use the peripheral and a computer using a second computer/peripheral scheme to use the peripheral.
In general, in another aspect, the invention features transmitting a request for information to a peripheral from a computer conforming to a first computer/peripheral scheme to a peripheral conforming to a second computer/peripheral scheme, and receiving a reply from the peripheral in response to the request that includes information that causes the computer not to use the device.
In general, in another aspect, the invention features a computer program product, disposed on a computer readable medium, that includes instructions that cause a processor to transmit a request for information to a peripheral, and based on a reply received from the peripheral, determine whether the peripheral conforms to a first or second computer/peripheral scheme.